package manayShape_Polymorphism2;

import java.util.ArrayList;
import java.util.Collections;

//Cage:笼子
public class Cage1 {
    public static void main(String[] args) {
        ArrayList a=new ArrayList();
        a.add(21);
        a.add(12);

        Collections.sort(a);

        System.out.println(a);//12,21
    }

}



//Animal[]  animals=new Animal[2];

